Clutch control mechanism



H. W. PRICE CLUTCH CONTROL MECHANISM Aug. 1, 1950 3 Sheets-Sheet 1 Filed Nov. 20, 1943 uwavme BY #12010 W Ha os 1, 1950 H. w. PRICE 2,517,025

CLUTCH CONTROL MECHANISM Filed Nov. 20, 1943 3 Sheet-Sheet 2 s- 1, 1950 H. w. PRICE 2,517,025

CLUTCH CONTROL MECHANISM Filed Nov. 20, 1943 3 Sheets-Sheet 5 lflfl //4 Patented Aug. 1, 1950 CLUTCH CONTROL MECHANISM Harold W. Price, South Bend, Ind., assignor to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Application November 20, 1943, Serial No. 511,085

relates to power means for operating a friction clutch to effect both an engagement and disengagement of said clutch.

One of the objects of my invention is to provide, in an automotive vehicle comprising a vehicle speed responsive governor, a friction clutch devoid of means for engaging the clutch, an accelerator, and a transmission and clutch controlling shift lever, a pressure diiferential and spring operated double-acting motor unit operable at the will of the driver, by his operation of the accelerator and shift lever, to effect an operation of the clutch.

Yet another object of the invention is to provide, in the power plant of an automotive vehicle, power means for moving the driven element of a friction clutch into and out of engagement with the driving element of said clutch thereby effecting respectively an engagement and disengagement of said clutch, said power means including a pressure differential and spring operated double-acting motor unit consisting of two separate motors and further including valve means for controlling the operation of said motor unit, said means including the accelerator operated throttle of the carburetor of the vehicle and further including a three-way valve controlled both by the gear shift lever of the vehicle and a vehicle speed responsive governor.

Myinvention also eomprehends the provision of a friction clutch control mechanism for an automotive vehicle said mechanism including a pressure differential and spring operated motor unit operably connected to a friction clutch of the aforementioned type, said motor unit including two separate motors, one of said motors being controlled by an operation of the carburetor throttle valve of the vehicle and operative to effeet a so-ealled first stage of engagement of the clutch and the other motor being controlled by said carburetor throttle valve and by either the shift lever of the vehicle or a vehicle speed responsive governor and operative to effect a socalled second stage of engagement of the clutch. Yet another object of my invention is to provide power means, including a pressure differential and spring operated motor unit, for effecting an engagement of a friction clutch including a driving element and a driven element, said power means further including spring means operative to effect a separation of said clutch elements that is a disengagement of said friction clutch.

A further object of my invention is to provide power means for effecting a smooth engagement of an automotive friction clutch when the accelerator of the vehicle is suddenly depressed to start the car in motion.

Other objects of the invention and desirable details of construction of parts will become apparent from the following detailed description of a single embodiment of the invention, taken in conjunction with the accompanying drawings illustrating said embodiment, in which:

Figure 1 is a diagrammatic view disclosing the features of the friction clutch and the clutch operating power means constituting my invention;

Figure 2 discloses in section the clutch operating pressure differential and spring operated motor unit of my invention together with a portion of the valve mechanism for controlling the operation of said unit; and

Figure 3 is a longitudinal sectional view of the valve mechanism disclosed in Figure 2.

Referring now to Figure 1 disclosing a preferred embodiment of the combined friction clutch and clutch operating power means constituting my invention a clutch operating doubleacting pressure difl'erential and spring operated motor unit i0, shown in detail in Figure 2, is connected to a friction clutch 12, Figure 1, said clutch being distinguished by the absence of the usual clutch springs. This clutch includes a casing ll fixedly mounted on the casing of a change speed transmission I6 said transmission being drivably connected to the driven member l8 of the clutch by means including a shaft 20. This driven member of the clutch is provided at its outer periphery with the usual friction mat 22 one face of said mat being movable into engagement with the inner face of a clutch driving member 24 which is drivably connected to the internal combustion engine of the vehicle, not shown. Now the clutch driven member I8 is preferably so constructed that the mat 22 moves slightly away from the clutch driving member 24 when the clutch operating power means of my invention is rendered operative to disengage the clutch.

Describing now the force transmitting means interconnecting the driven clutch member l8 with harness the power elements of motor wait 96, said means includes a connecting rod 26, Figure 2, adjuetabiy connected to a link 28. This iink is pivotally con-- nected to one end of one arm of a crank member 66 pivotally mounted, that is fulcrumed, upon a fixedly mounted pin 82. arm of the crank member 36 is pivotally connected to a link 66 which is adiustably connected to one arm of a lever 36. This lever is fulcrumed upon the rounded end of a stud 68. which is fixedly secured to the clutch casing member M. The lower arm 36 of the lever 36 preferably lies within a slotted portion Bl of a thrust member 66 sleeved over and slidably mounted upon the shaft 26. A thrust ring 62 mounted on the thrust member 66 is at all times in contact with crank members 66 pivotally mounted upon a clutch housing member 66 secured to the clutch driving member 26. The cranks 66 may be pivotally connected at 66 with a thrust plate 68 contactable with the outer face of the friction mat 22: or the cranks 66 may be in disconnected eng ement with said thrust plate thereby permitting the mat 22 to move out of engagement with the driving clutch element 26 when the clutch operating power means of my invention is operative to disengage the clutch.

A tension spring 56 interconnecting the clutch casing i6 and the lever 36 and tension springs 52 interconnecting the cranks 66 and casing member 66 constitute the principal parts of the power means for effecting a disengagement of the clutch that is the movement of the mat 22 of the driven clutch member away from the clutch driving member 26. A foot operated clutch pedal 61, connected to an arm 69 of the crank member 36 by a link serves as a means to make possible a disengagement of the clutch in the event of failure of the springs 52 and the spring 66.

Referring now to Figure 2 disclosing the principal feature of my invention that is the pressure differential and spring operated motor unit I6, this unit consists of two separate motors, a so-called first stage clutch engaging motor 66 and a clutch engaging motor 56; and as will be described hereinafter the latter motor also serves as a part of the power means for effecting a disengagement of the clutch.

The motor unit I6 includes a cup shaped casing member 56 and a ring 59 secured together by bolts 62 the member 56 together with a piston 6| constituting the motor 66 and a casing member 66 together with a diaphragm power element 66 constituting the motor 56. The casing member 66 and the power element 66 are secured together by bolts 63. The connecting rod 26 is secured to the power element 66 by a nut 65 and the upper portion of said element is telescoped within a hollow rod 66 which is threadedly connected to the hub portion I6 of said piston. The upper end of the connecting rod 26 contacts a compression spring I2 housed within the rod 66, said spring serving to make the connection between the piston 6| and the driven clutch element a yieldable one. A compression spring I6, interposed between the piston 6I and the upper end, Figure 2, of the cup shaped member 56 is one of the principal parts of the motor unit I6 in its operation of effecting an engagement of the clutch.

The motor 56 of the motor unit I6 is controlled in part by a solenoid operated three-way valve unit I6 disclosed in detail in Figure 3, said unit comprising casing members I6 and 86 and a disk member 62 detachably secured together by suit- The end of another able fastenings such. as bolts 66. The casing memnected to one end of said armature. As disclosed in Figure 1 the solenoid winding 66 is wired in series with the ignition switch 62 of the ignition system of theear, agrounded battery 66 and a grounded breaker switch 36. The latter switch is operated by the shift lever. 66 of the car, said switch, and the force transmitting means interconnecting the switch with the shift lever. being so constructed and the parts thereof so arranged that the switch is closed during the first increment of movement of the shift lever and opened during the last increment of movement of said lever. The winding 66 is also wired in series with the battery, ignition switch and a grounded vehicle speed responsive governor operated switch I66. Therefore it follows that the switches 96 and I66 are in parallel in the electrical circuits. The governor operated switch I66 is closed by the governor when the speed of the car is reduced to or below a certain factor.

Briefly describing the operation of the unit 16 when the solenoid is energized, by either reducing the speed of the car below governor speed or by moving the shift lever to operate the transmission I6, then the valve member 66 is seated to cover an opening I62 in the disk member 62 thereby interconnecting the intake manifold I66 of the engine with a control chamber I66 of the motor 56. Tracing this air transmitting connection the same includes a conduit I66 interconnecting the manifold with the valve unit 16, a duct I I6 in said unit, a chamber I I2 in said unit, and a conduit 6 interconnecting the chambers I66 and H2. The conduit 6 has incorporated therein a spring and pressure differential operated check valve II6 the operation of which is described hereinafter. When the solenoid of the unit I6 is deenergized a spring I I6 within said unit functions to seat the valve member 66 to cover the end of the duct II6 thereby venting the motor chamber I66 to the atmosphere via a port I26 in the unit I6, a chamber I22 in said unit, the opening I 62, the chamber H2 and the conduit I I6.

Describing now the valve means for controlling the motor 66 and in part controlling the motor 66 the principal part of said valve means is simplythe throttle or so-called butterfly valve I26 of the carburetor I26 of the vehicle. The other part of this control valve means constitutes a small part of the body section I26 of the carburetor said part being provided with an opening I36; and this opening registers with one end of a conduit I32. This conduit is connected at its other end with a hollow nipple-I36 connected to the casing 66 of the motor 66. When the accelerator 6| is completely released to thereby completely close the throttle valve I26 as disclosed in Figure 1 then the edge of said valve adjacent the opening I36 lies below said opening accordingly the gaseous pressure at said opening and within the conduit I32 is atmospheric or substantially so; and it follows therefore that the gaseous pressure within a control chamber I36 of the motor 56 is at this time atmospheric or substantially so. The motor 66 is then said to be deenergized. Now when the accelerator is depressed to open the throttle valve I26 the aforementioned edge portion of said valve is moved clockwise that is in the direction of the arrow, Figure l, to a position above the opening I36 resulting in a relatively rapid flow of air through the body sections I20 and the Venturi effect of this flow of air across the inner end of the opening I30 results in a flow of air through the conduit I32 from the chamber I35 to partially evacuate said chamber. Now the degree of vacuum created in the chamber I35 is directly proportional to the rate of flow of air through the air induction conduit I20, and this rate of flow of air is determined in large measure by the speed of the engine and the degree of opening of the throttle valve I24. Explaining the creation of this clutch engaging force when the chamber I35 is partially evacuated the motor 54 is energized for the power element 55, is then subjected to a differential of pressures, said element being subjected to the pressure of the atmosphere on its upper side via a vent port I" in the casing member 50 and a pressure less than atmosphere on its lower side.

Describing now the operation of the mechanism constituting my invention, when the car is at a standstill and the internal combustion engine is idling then the clutch is disengaged; for at this time the throttle valve I24 is in its closed position as disclosed in Figure 1 thereby creating, by virtue of the pumping action of the pistons of the engine, a partial evacuation of the intake manifold I04. It follows therefore that the control chamber I05 01' the motor 55 is likewise partially evacated inasmuch as the valve member 00 is at the time positioned to interconnect said chamber with the manifold: for it will be remembered that when the car is at a standstill the governor operates to close the switch I00 which results in an energization of the solenoid of the unit 15.

Now when the control chamber I06 is partially evacuated the motor 55 is energized by vacuum resulting in a movement or the power element 6| upwardly to compress the spring 14; and this operation, together with a deenergization Of the motor 54, makes possible an operation of the spring 50 and the springs 52 to effect a disengagement of the clutch. As to the deenergization of the motor 54 this is effected as explained above, when the throttle valve I24 is closed.

The clutch having been disengaged by the slight separation of the driving and driven elements of the clutch. the driver will then probably operate the selector lever 98 to establish the transmission It in its low gear setting and this having been done he will then depress the accelerator, not shown, to open the throttle valve I24 to effect both a speeding up of the engine and an engagement of the clutch.

Describing in detail the latter operation the first stage of engagement of the clutch, that is the forcing of the mat 22 of the driven clutch element I8 into engagement with the driving clutch element 24, is effected, with a normal operation of the accelerator, solely by the energization of the motor 54; for as previously described when the throttle valve I24 is opened said motor is energized the degree of said energization being directly proportional to the rate of flow of air past the opening I30. Now inasmuch as the clutch elements are only slightly separated when the clutch is disengaged it follows that said elements are relatively quickly brought into engagement to start the car in motion; and the acceleration of the car is increased as the loading of the clutch plates is increased with a speeding up of the engine. As described above, the clutch plate loading is directly proportional or substantially directly proportional to the energization of the motor 54 and said energization is dependent upon a 6 two variables, the engine speed and the throttle opening.

When the car speed reaches the so-called governor speed, that is the speed of the car at which the governor operates to open the switch I00, then the second stage of clutch engaging operation of the clutch control mechanism is initiated; for when the switch I00 is opened the solenoid of the unit 15 is deenergized to move the valve member to the position disclosed in Figure 3 thereby admitting atmosphere at a fixed rate into the chamber I06. This fixed rate is effected by an opening I40 in the check valve H5. The motor 56 is then energized as a result of the expansion of the spring 14 the rate of said expansion, to increase the loading of the clutch members, being constant by virtue of the fixed rate of bleed of air into the chamber I06. There is thus effected the second and final stage of engagement of the clutch to completely load the clutch elements in contact with each other and thereby prevent a slipping of the clutch.

Should the driver depart from a normal operation of the accelerator by depressing the same very suddenly to its wide open throttle position y then the motor 56 becomes the sole means for effecting the engagement of the clutch; for with such an operation of the accelerator, which is usually eifected in starting the car from rest, the energization if any of the motor 54 is insufllcient to effect a loading of the clutch elements. .The motor 56 is then spring energized to progressively increase the loading of such elements to get the car under way.

Describing this operation in detail with a sudden opening of the throttle the manifold vacuum is suddenly-dropped and the gaseous pres sure within said manifold increases to atmos- -pheric or substantially so. Air is thus bled into the chamber I06 to effect the aforementioned spring energization of the motor 56, via the connection between the manifold and said chamber it being remembered that with the above operation the check valve H8 is closed as disclosed in Figure 2.

After the vehicle is under way in low gear above governor speed and the desired vehicle speed is reached the driver, to successively disengage the friction clutch and establish the transmission in a higher gear ratio, needs but to first release the accelerator and then move the shift lever to the desired position. As described above the first increment of movement of said lever serves to close the switch 96 thereby effecting a disengagement of the clutch. Then after the transmission is established in gear and the driver removes his hand from the shift lever said removal will, by virtue of the opening of the switch 96, serve to initiate the second stage clutch engaging operation of the motor 56. The driver however probably does not delay the depression of the accelerator accordingly the so-called first stage engagement of the clutch is probably well under way or completed before the spring 14 has completed its operation of loading the clutch elements.

There is thus provided a simple power means for operatingthe friction clutch of an automotive vehicle, said clutch being devoid of the usual springs for maintaining the clutch engaged. The disengagement of the clutch is effected by releasing the accelerator together with either a slowing down of the vehicle to its governor speed or a gear changing operation of the selector lever; and the engagement of the clutch iseflected by depressing the accelerator together with either a removal of the hand from the shift lever after a gear shift movement thereof or an increase in the speed of the vehicle above its governor speed. It is to be particularly noted that a smooth engagement of the clutch is eifected inasmuch as with the mechanism of my invention the loading of the driving and driven clutch elements is, with a normal operation of the accelerator, proportional to the speed of the engine and degree of the opening of the throttle valve. In other words with the clutch control mechanism of my invention the loading of the clutch elements is, with a normal operation of the accelerator, proportional to the torque of the engine said torque being the resultant of the throttle opening and the engine speed. There is thus insured the desired acceleration o the vehicle under all driving conditions.

I claim:

1. In an automotive vehicle providing an accelerator, a friction clutch including driving and driven elements, and a transmission and clutch controlling shift lever, power means for effecting both an engagement and a disengagement of said clutch, said power means including a double-acting motor unit comprising two power elements and force transmitting means interconnecting said elements with the clutch, valve means, including an accelerator operated valve member, for controlling the operation of said motor unit, means for operating said valve means comprising a solenoid and means for controlling the operation of the solenoid including a switch operated by the aforementioned lever.

2. In an automotive vehicle provided with a carburetor and an accelerator, a friction clutch including driving and driven elements, and a transmission and clutch controlling shift lever, power means of itself efiecting both an engagement and a disengagement of 'said clutch, said power means including a double-acting motor unit comprising two separate-motors and valve means for controlling the operation of the two motors of said motor unit, said means including an accelerator operated valve member which also constitutes a part of the aforementioned carburetor and further including a solenoid operated three-way valve controlled in part by an operation of the aforementioned lever.

3. Clutch control mechanism for an automotive vehicle including in its power plant a carburetor, an accelerator, a friction clutch having driving and driven members and a transmission and clutch controlling shift lever; power means for effecting both a disengagement and an engagement of said clutch, said means including a doubleacting motor unit operably connected to the clutch, valve means for controlling the operation of said motor unit including an accelerator operated valve member which also constitutes the throttle valve of the carburetor and also including a power operated three-way valve, means for operating the latter valve including a solenoid and means for controlling the operation of said solenoid including a switch operated by the aforementioned shift lever and further including 9. vehicle speed responsive governor operated switch.

4. In an automotive vehicle having a power plant comprising an accelerator, a carburetor, a

- vehicle speed responsive governor, a friction clutch having driving and driven members, and a transmission and clutch controlling shift lever, power means for effecting, both an engagement and a disengagement of the clutch, said power means including a double-acting pressure differential and spring operated motor unit consisting of two separate motors each having a power element.

force transmitting means interconnecting the driven element of the clutch with said power elements, valve means for controlling the operation of the two motors of said motor unit said valve means including the throttle valve of the carburetor and said valve means further including a solenoid operated three-way valve controlled by a switch operated by the shift lever and further controlled by a switch operated by the vehicle speed responsive governor.

5. In an automotive vehicle having a power plant comprising an accelerator, a carburetor, a vehicle speed responsive governor, a friction clutch having driving and driven members, and a transmission and clutch controlling shift lever. power means for efiecting both an engagement and a disengagement of the clutch, said power means including a double-acting pressure diflerential and spring operated motor unit consisting of two separate motors each having a power element, force transmitting means, including a yieldable member which is compressed when the clutch is engaged, interconnecting the driven element of the clut h with said power elcments, valve means for controlling the operation of the two motors of said motor unit said valve means including the throttle valve of the carburetor which is operative, with a normal operation of the accelerator, to control the operation of one of said motors and said valve means further including a solenoid operated three-way valve for controlling the operation of the other of said motors, said valve being controlled by a. switch operated by the shift lever and further controlled by a switch operated by the vehicle speed responsive governor.

6. In an automotive vehicle provided with a power plant including an accelerator, a transmission and clutch controlling shift lever and a clutch having a driving member and a driven member including a friction mat at its outer periphery said latter member being so constructed and positioned with respect to the driving memv her that the friction mat is biased to a position slightly spaced from the outer periphery of the driving member; power means for moving the friction mat into engagement with the driving member to engage the clutch and for making possible a movement of said mat away from said driving member to disengage the clutch, said power means including a double-acting pressure difl'erential and spring operated'motor unit, valve means for controlling the operation of said motor unit and means for operating and controlling the operation of said valve means including a vehicle speed responsive governor, a. switch operated by said governor and a switch operated by the aforementioned shift lever.

HAROLD W. PRICE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,994,835 Sanford et al Mar. 19, 1935 2,002,367 Fahrney May 21, 1935 2,084,380 Bragg et al June 22, 1937 2,123,867 Criley July 19, 1938 2,129,358 McCollum et al Sept. 6, 1938 2,130,848 Kliesrath Sept. 20, 1938 2,191,669 Kress Feb. 27, 1940 2,250,835 Kliesrath et a1 July 29, 1941 2,294,823 Andres Sept. 1, 1942 2,341,587 Andres et a1 Feb. 15, 1944 

